JPS585252B2 - Zirconium sponge Ruino Seizouhouhou Oyobi Sonosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining a zirconium sponge by reducing zirconium halide with magnesium or sodium.

The conventionally known industrial manufacturing method for zirconium sponge is to charge bulk or powdered zirconium tetrachloride purified by sublimation together with magnesium or sodium into a reaction vessel, and then heat the sponge to a very high temperature under an inert gas. The manufacturing method involved raising the temperature and gradually bringing the zirconium tetrachloride gas into contact with magnesium or sodium, etc., in order to suppress the temperature rise caused by a rapid reaction.

This conventional method has extremely disadvantageous industrial problems as described below.

(1) A large amount of space is required to charge the reactor with pre-purified bulk or powdered zirconium tetrachloride, and the reaction container itself has a large capacity.

Therefore, the reaction is carried out only once per batch, and the volume of the zirconium sponge occupied in the reaction container is approximately 1/8.

(2) Zirconium tetrachloride charged into the reaction vessel is then reacted with magnesium, so it needs to be heated to a high temperature gas (340°C to 400°C), which requires a large amount of heating energy. do.

(3) During the reduction reaction, the quality is degraded by trace amounts of nitrogen and oxygen, so the reaction vessel should be filled with an inert gas (for example, argon) or the internal pressure of the reaction vessel should be at least atmospheric pressure. Gauge pressure 0.2-1.0kg/cm
2 is filled with inert gas.

By the way, as the temperature of the reaction vessel rises, the internal pressure also rises, so the reduction reaction is carried out by releasing an inert gas and adjusting its partial pressure, but this released gas also contains the coexisting zirconium tetrachloride gas. Therefore, the amount is a loss.

Also, during discharge, the relatively low temperature part of the valve (below 331℃)
Zirconium tetrachloride solidifies and causes blockages in valves, pressure measuring pipes, etc.

(4) The reduction reaction temperature rises to about 1000°C, so the reaction vessel is made of a heat-resistant alloy, but if too much inert gas is released, the zirconium tetrachloride gas becomes too concentrated and the reaction takes place. If the reaction proceeds rapidly and the heat produced by the reaction becomes large and the reaction vessel reaches a high temperature of 935°C, Fe-Zr eutectic will occur and the vessel will be damaged.

Therefore, an alloy of the reaction vessel material (Fe, Cr) and Zr is formed, which causes a deterioration in the quality of the zirconium sponge.

On the other hand, if too little inert gas is released, the reduction reaction becomes extremely slow and the reduction time becomes extremely long, which is extremely disadvantageous economically.

Since the release of these inert gases is arbitrarily mixed with zirconium tetrachloride gas, a method for measuring the ratio has not yet been put to practical use, and in actual operation, an appropriate mixing ratio must be determined by the judgment of an expert. A reduction reaction is performed by releasing a mixed gas.

Therefore, there is a large variation in quality between batches, and this variation could not be avoided in the past.

In view of the drawbacks of the conventional batch-by-batch reaction method described above, the present inventors added zirconium halide gas in small amounts at a time into a reaction vessel containing a reducing agent such as magnesium or sodium in advance. We proposed a method for causing a reaction by supplying the gas, and the content thereof is described in Japanese Patent Application No. 48-29932 (Japanese Unexamined Patent Publication No. 48-29932 (Japanese Unexamined Patent Publication)
-118.608) disclosed in the specification and drawings.

However, the invention according to the applicant's earlier application involves supplying gaseous zirconium halide into a reaction vessel with an inert gas atmosphere, as described above.
The drawbacks of the conventional methods (3) and (4) described above are not improved, and in addition to this, the above-mentioned drawbacks in the conventional methods of (3) and (4) are not improved, and in addition, the reaction is caused by contacting the mixture of the zirmanium halide gas and the inert gas with the reducing agent during the reaction. Therefore, there is a drawback that there is little contact between the zirmanium halide in the liver and kidneys and the reducing agent, and the reaction rate is slow.

By the way, the method according to the applicant's earlier application is a reaction between zirconium tetrachloride gas and magnesium, as described above, and is an industrial method in which solid zirconium tetrachloride is directly charged into a reaction vessel in reaction amounts. No known attempts.

The reason for this is that it is difficult to prepare powdered zirconium tetrachloride, which does not contain impurities that adversely affect metallic zirconium, especially oxygen, and there are also problems with the method of charging this raw material into a high-temperature reaction vessel. It is assumed that this was considered too much and was a hindrance to its realization.

In other words, zirconium tetrachloride, which has the unique physical property of sublimating from solid to gas to solid at 331°C, exists as a gas during the reduction reaction because the temperature inside the reaction vessel is high, or if a supply device is connected to the reaction vessel. In this case, it was generally thought that a temperature zone of 331° C. would inevitably be created in a certain area, where zirconium tetrachloride would solidify and become an obstacle to the supply and charging of zirconium tetrachloride.

Focusing on this point, the present inventor further conducted various studies and experiments, and as a result, firstly, zirconium tetrachloride was purified using a separate device, and this was continuously fed into a reaction vessel to produce the tetrachloride of the above-mentioned earlier application. We have discovered a method for producing zirconium of high quality and under conditions that are industrially more economical than the case of the reduction reaction of zirconium with gas.

That is, the purpose of this invention is to solve the disadvantageous problems of the conventional method mentioned above, and also to make it possible to produce zirconium sponge industrially with high efficiency and economically. By directly supplying zirconium chloride to the reaction vessel using a supply device to carry out the reduction reaction, there is no loss of zirconium tetrachloride, there is no clogging of valves, etc., and the reaction rate is accelerated. After the first reduction reaction, the zirconium sponge that was produced only occupied about 1/8th of the volume of the zirconium sponge, which was produced after the first reduction reaction, was left in the reaction container, and the magnesium chloride produced by the reduction reaction was extracted. Next, by repeating the operation of charging molten magnesium and carrying out the reduction reaction again several times, zirconium is produced up to about 1/3 of the volume of the reactor, for example.

Therefore, in this invention, an alkaline earth metal or alkali metal reducing agent is stored in advance inside the reaction vessel, and the reaction vessel is filled with an inert gas from an internal pressure adjustment pipe for introducing and discharging inert gas. The zirconium halide is supplied by the supply device so that the zirconium halide is brought into contact with the alkaline earth metal or alkali metal reducing agent to perform a reduction reaction, and a tip opening is provided in the middle part of the reaction vessel. In the method for producing a zirconium sponge, the molten salt produced by the reduction reaction is extracted from the reaction vessel through an operation pipe with a protruding section, and the reduction reaction is continued by adding a reducing agent as appropriate. First, a predetermined amount of zirconium halide in a solid state is directly supplied into the reaction vessel at the start of the reaction, and this solid zirconium halide is brought into contact with the above-mentioned reducing agent while in a solid state to perform an initial reduction reaction. After this initial reduction reaction is completed, the molten salt produced by this initial reduction reaction is extracted, a reducing agent is additionally charged, and a predetermined amount of zirconium halide, which remains solid, is sequentially fed into the reaction vessel from the above-mentioned supply device. A method for producing a zirconium sponge is characterized in that the solid zirconium halide is directly supplied, and the solid zirconium halide is brought into contact with the reducing agent to continue the reduction reaction.

Next, a method for manufacturing a zirconium sponge according to a first embodiment of the present invention will be explained with reference to FIGS. 1 and 2.

Figures 1 and 2 show an example of an apparatus used to carry out the method of the present invention, in which 1 is a reaction vessel having an opening on the top surface, 2 is a vertical cylindrical partition, and 3 is an opening on the bottom surface. It is a condensate adhesion container having mounting flanges 4, 4 formed on the upper and lower edges of the partition 2, and mounting flanges 5, 6 formed on the upper edge of the reaction container 1 and the lower edge of the adhesion container 3, respectively. are fixed with bolts 7 through backing, so that the three parts 1, 2, and 3 are vertically connected, and the inner wall surface of the partition 2 is further inner than the inner wall surface of the reaction container 1 and the adhesion container 3. It is protruding towards the side.

These reaction vessel 1, partition stand 2, and adhesion vessel 3 are all housed in electric heating furnaces 8, 9, and 10, and reaction vessel 1
An adjustment space 11 is formed between the outer periphery of the electric furnace 8 and the inner periphery of the electric heating furnace 8, and adjustment pipes 12,
12 is open.

33 is a bottom plate of the reaction vessel 1, and the zirconium sponge is taken out by punching out this bottom plate.

Reference numeral 13 denotes a feeding device consisting of a screw feeder for supplying ZrCl4, the tip of the outer cylinder 14 is opened on the inner wall of the partition 2, and the base end of the outer cylinder 14 has a ZrCl4-filled lobe on the upper surface. 15 are provided with branching protrusions.

Further, as shown in detail in FIG. 2, the rotary shaft seal of the screw shaft 16 at the sealed base end of the outer cylinder 14 first seals the zirconium tetrachloride gas with the inner Teflon gasket 17, and seals the atmosphere. It has a structure in which the shaft is sealed with an outer rubber O-ring 18.

19 is a driven sprocket attached to the protruding base end of the screw shaft 16, and 20 is a bearing.

Furthermore, the screw shaft 16 has a pipe shape with its proximal end open and its inner end surface closed, and a sheathed heater 22 is inserted into the inner cavity 21 of the screw shaft 16 .

A rotary feeder 23 is placed on the inlet vibrator 15.
are connected, and the upper part is ZrC containing purified ZrCl4.
14 storage tank pin 24.

25 is a shelf hanging prevention device.

The screw feeder 13 and rotary feeder 23 are designed to rotate in conjunction with each other, but the screw feeder has a much larger feeding capacity than the rotary feeder.

Reference numeral 26 denotes an operation pipe, the tip of which protrudes horizontally from the inner wall surface of the partition 2, is bent vertically downward, and is positioned approximately at the center of the reaction vessel 1. The end is connected via a valve 27 to a MgCl2 extraction or Mg charging device.

Reference numeral 28 designates an internal pressure adjustment pipe for introducing and discharging inert gas such as Ar, which is opened on the inner wall surface of the partition stand 2, and 29 designates a valve thereof.

Further, the inner wall surface of the partition stand 2 at the upper position of the protruding openings of the pipes 26 and 28 is provided with MgC after the completion of the reduction reaction.
Punched plate 3 that serves as a gas passage for vacuum distillation to extract l2
0 is welded.

Furthermore, an exhaust pipe 31 that communicates with a vacuum pump is connected to the top of the condensate adhesion container 3, and a punching rod 32 that opens a passage in the punching plate 30 in the vertical inward direction is provided at the top. It is installed so that it can be moved up and down.

Next, the operation and effect of the above device will be explained.

First, after the pipe 28 is exhausted, a calculated amount of magnesium is poured into the reaction vessel 1 into which Ar is introduced, within the limit that the molten surface of magnesium chloride produced as a by-product after the reaction rises to the upper end of the reaction vessel 1. Load it in advance.

Next, the magnesium is melted in the attached electric furnace 8,
After reaching the reaction start temperature (750 to 850°C), the rotary feeder 23 and the screw feeder 13
Accordingly, the purified powdered zirconium tetrachloride in the storage bottle 6 is supplied into the reaction vessel 1 to undergo a reduction reaction.

In this way, the desired zirconium sponge is produced on the bottom and inner wall surface of the reaction vessel 1.

The feed rate of the powdered zirconium tetrachloride according to the reaction amount is automatically adjusted by the rotary feeder 23 according to the change in the pressure inside the reaction vessel (reaction rate).

Furthermore, as described above, since the supply capacity of the screw feeder 13 is much larger than that of the rotary feeder 23, there is no closure due to compression of the feedstock.

Furthermore, the exit portion of the screw feeder 13 is approximately 600 mm
℃, while the rotary feeder 23 is at room temperature, but since the screw shaft 16 is heated by the internal sheathed heater 22, the temperature gradient is smooth and the low temperature powdered tetrachloride is heated. Even if zirconium and high-temperature gas flow countercurrently within the outer cylinder 14, no solidification phenomenon occurs.

Furthermore, even if a small amount of zirconium tetrachloride solidifies on the blades of the screw shaft, it can be reevaporated by adjusting the heat output of the sheathed heater 22.

Furthermore, since the rotary shaft seal of the screw shaft 16 rotates at a low speed, there is no problem with airtightness.

After the above initial reduction reaction operation is completed, the internal pressure adjustment pipe 28
Then, inert gas (Ar gas) of usually 1.2 to 1.5 kg/cm2 above atmospheric pressure is added, and MgCl2 is extracted to the level of the tip of the operation pipe 26. Next, the molten Mg is poured into this pipe using another device. 26, and again ZrCl
4 is transported and supplied to perform a reduction reaction, and further MgCl
2 was removed and molten Mg was additionally charged.

The zirconium sponge performs the above operation using the operation pipe 26.
The reduction reaction is repeated until it is deposited up to the tip of the layer.

By the above method, more than three times as much zirconium as the conventional production amount can be produced in one batch.

Now, when the above reduction reaction operation is completely completed, the punching rod 32 is lowered to punch out the punching plate 30, and the exhaust pipe 3
Activate the vacuum pump via 1.

Thereafter, when the electric heating furnace 8 is further operated to raise the temperature of the reaction vessel 1, MgCl2 in the vessel 1 is vacuum distilled and condensed and adheres to the inner wall surface of the deposition vessel 3, which has been kept at a relatively low temperature.

During the high-temperature vacuum distillation operation, the adjustment pipe 12 is
, 12, and the adjustment space 1 on the outer periphery of the reaction vessel 1.
Make sure to keep 1 in a vacuum.

Further, nitrogen or cold air can be introduced into the adjustment space 11 to cool the outer surface of the reaction vessel 1 in order to remove reaction heat and further accelerate the reaction rate during the reduction reaction operation.

After completing each of the above operations, the adhesion container 3 and the partition stand 2 are removed, and the zirconium sponge inside the reaction container 1 is pushed out from the bottom plate 33 and taken out.

The height of this zirconium sponge mass is larger than its diameter, and the low-grade sponge parts on the circumference and top and bottom surfaces are removed using a lathe, etc., and several batches of sponge mass are welded to form consumable electrodes for vacuum melting furnaces used to manufacture ingots. It can be provided to

EXAMPLE Next, an example of the present invention using the above-mentioned zirconium reduction production apparatus will be described below.

Powdered ZrCl4110 purified by sublimation using another device
kg is charged into the ZrCl4 storage bin 24, and the screw feeder 13 and rotary feeder 23 are assembled and attached as shown in FIG.

Reaction vessel 1 contains 40% more than theoretically 12
kg of Mg ingots are put therein, and a partition stand 2 with a punched plate 30 welded to its upper part and a vapor deposition container 3 are installed by sandwiching a rubber backing and tightening the ports.

After the airtightness test, the reactor is evacuated from the internal pressure adjustment pipe 28 and allowed to flow to an Ar gauge pressure of 0.2 kg/cm2.

Ar is also introduced into the storage bin 24 through the gap between the screw feeder and the rotary feeder.

Insert the heat furnace 8 during exhaust and heat the inside of the reaction vessel to 200 to 300
After preheating to 750°C or passing Ar, the temperature is further increased to 750°C.

During that time, the pressure of Ar in the reaction vessel increases due to thermal expansion, but if it becomes 0.5 kg/cm2, then the pressure will increase by 0.2 kg/cm2.
Release to the outside up to cm2.

Since it uses only Ar, there is no valve blockage.

When the temperature inside the reaction vessel reaches 750°C, the pressure inside the vessel is reduced to 0.
The weight was lowered to 11 kg/cm2, and the screw feeder and rotary feeder were driven to start supplying ZrCl4.

ZrCl4 supplied to the reaction vessel is reduced near the Mg dissolution surface by the reaction ZrCl4+2Mg→Zr+2MgC12, but a part of it sublimes into gas due to the high temperature and shows a slight pressure increase.

If the supply of ZrCl4 is then stopped, gaseous ZrCl4
is also reacted, and the pressure drops to the original 0.11 kg/cm2.

Next, ZrCl4 is supplied again, and when the pressure rises to 0.4 kg/cm2, the supply is stopped, and the reduction reaction is continued while repeating the operation of supplying ZrCl4 again at 0.1 kg/cm2.

The on/off operation of the supply device is automatically performed by interlocking the pressure regulator and the supply device.

While feeding with the screw feeder, the sheath heater 22 inside the shaft is inserted and the screw shaft 16 is
Heat to 0-350°C.

The above intermittent supply lasted for 1.5 hours, and the average supply rate of ZrCl4 was 28 kg/hr.

The completion of the reaction can be determined by the fact that there is no drop in pressure since Mg as a reducing agent is consumed.

After the above reduction reaction was completed, 222 kg of MgCl was extracted from the operation pipe 26 by pressurizing Ar to a level slightly higher than atmospheric pressure.

Next, 5 kg of molten Mg is poured into pipe 26 from another Mg melting furnace.
Then, the pressure was increased to 0.1 kg/cm again.
2 and started refeeding ZrCl4.

This second reduction reaction finished in 35 minutes and the MgC
l2 was 14 kg, and the feed rate was 27 kg/hr.

Following the same reaction operation, the total reaction time was 3.7 hr.
, Zr production amount is 38kg extracted, MgCl4 is 64k
It was g.

The details of the quantity balance in the above example are summarized in the following table.

Further, a comparative example will be shown below in which the same amount of zirconium sponge was manufactured by the solid supply method according to the present invention and the sequential gas supply method.

A comparison of the production speed between the method of the present invention and the method of the prior application in the same scale equipment is as follows.

Prior application method 10/8 = 1.25 kg/hr As mentioned above, the solid supply method according to the present invention has a rate of 10.3/1.25 = 8.24 and 8.2 compared to the gas supply method of the prior application.
The reaction rate is four times faster, but this is because according to the method of the present invention, solid zirconium halide is not mixed into the inert gas when it is supplied, but instead falls onto the reaction surface as it is. This is because a concentrated gas layer of zirconium halide is formed along the reaction surface during the reaction, and the zirconium halide gas does not diffuse into the inert gas as in the gas supply method of the previous application, and the reaction density is extremely high. be.

Furthermore, according to the method of the present invention, the reaction is instantaneous, and it appears that partially solid ZrCl4 and Mg are directly reacting.

Next, the heat generated by the solid supply method of the present invention and the gas supply method of the prior application in the case of the above embodiment will be explained.

First-to-file method: ZrZrC14(+2Mg(1)→Zr(S
)+2MgCl2(1) Heat of formation Knee ΔH877℃=78.6Kcal/hr Reaction rate: 1.25kg/hr (according to the above example) ) is obtained by subtracting the heat of sublimation (latent heat + sensible heat) of ZrC14 (S) → ZrZrC14 ().

78.6-40.5=38.1Kcal/mole Reaction rate: 10.3kg/hr (according to the above example)
As is clear from the above, the solid supply method of the present invention generates about four times more heat than the gas supply method of the prior application.

As described above, according to the method of the present invention, since a large amount of heat is generated, there is no need to heat the reaction vessel, and the reaction can be continued as it is, which is economical.

In this respect, according to the gas supply method of the earlier application, MgC in the reaction vessel
Heating is always required to prevent coagulation of l2.

Furthermore, according to the method of the present invention, as mentioned above, the heat of sublimation is constantly taken away from the heat generated during the reaction, so the heat generated does not become high compared to the reaction rate, and high-temperature corrosion of the reaction vessel can be suppressed. , operations such as depressurization during reaction are easy.

Although the above embodiments have been described in terms of transportation and supply using a screw feeder, it is possible to achieve the same objective by other methods.

That is, in the second embodiment shown in FIG. 3, ZrCl4 is pushed into the reaction vessel by a pusher 34 which is reciprocated by a piston motor or a hydraulic cylinder.

The third embodiment shown in FIG. 4 is a rotary feeder 23.
In this method, ZrCl4 is directly charged into the reaction vessel. After the reduction reaction is completed, the rotary feeder is removed and a device for vacuum distillation is installed.

In the second and third embodiments described above, parts corresponding to those in the first embodiment are given the same reference numerals and detailed explanations thereof are omitted.

The present invention can also be applied to magnesium or sodium reduction of niobium and tantalum halides.

According to the method for producing a zirconium sponge according to the present invention, a predetermined amount of solid zirconium halide is brought into direct contact with an alkaline earth metal or alkali metal reducing agent charged in advance in a reaction vessel, and reduced. It is characterized by carrying out the reaction and carrying out this reaction in at least two stages, an initial reduction reaction step and a continuing reaction step, each time forming a fresh reaction surface. Excellent effects can be obtained.

(1) According to the above method according to the present invention, the solid zirconium halide does not diffuse into the inert gas when it is supplied, but instead falls onto the reaction surface and reacts, so the reaction is direct and instantaneous. During the reaction, a concentrated gas layer of zirconium halide is formed along the reaction surface, and the zirconium halide gas does not diffuse into the inert gas as in the zirconium halide gas supply method of the earlier application. It has the effect of high density and fast reaction rate.

According to the example, the method of the present invention is 8.24 times faster than the method of the prior application.

(2) Also, according to the present invention, the above reaction is carried out in at least two stages: an initial reaction step and a continuing reaction step, and the molten salt resulting from the reaction is extracted each time, so that the reaction surface is kept fresh each time. This has the effect of further increasing the reaction density.

(3) According to the solid contact method of the present invention, since the reaction density is increased as described above, it is not necessary to maintain the reaction container at a very high temperature.

Therefore, Fe and Cr melting of the reaction container material and these Zr
Almost no eutectic occurs and a highly pure product can be obtained.

According to the above example, the iron impurity in the product is 0.0 according to the prior application method.
The amount of chromium impurities was significantly improved, as compared to 0.05% by the method of the present invention compared to 9% by the method of the present invention, and 0.005% by the method of the present invention compared to 0.01% by the prior application method.

(4) According to this invention, as mentioned above, the reaction container is not disturbed, and F
Since there is no possibility of contamination of e.g., Cr, etc., there is no need to cut out the outer periphery of the product, making it possible to achieve a high yield.

According to the example, the actual yield of the product according to the prior application method is 95%, while it is 97% according to the method of the present invention.

Since zirconium is an expensive metal, the high yield achieved by the method of the present invention is industrially very advantageous.

(5) According to the present invention, as described above, there is no need to maintain the reaction container at a high temperature, so the life of the reaction container is extended.

(6) According to the present invention, for the above-mentioned reason, the proportion of zirconium halide gas mixed in the reactive middle-aged active gas is extremely small, and therefore, zirconium halide is taken out to the outside together with the inert gas during depressurization operation. This method has the advantage that it is economical and does not cause blockage of the above-mentioned take-out pipe.

(7) According to the method according to the present invention, the heat generated during the reaction is about four times as large as that of the above-mentioned prior application method, so there is no need for heating to prevent coagulation of MgCl in the reaction vessel and promote the reaction. This has the effect of being economical.

(8) Furthermore, according to the solid supply method of the present invention, the heat of sublimation is always taken away from the heat generated during the reaction, so the heat generated does not become high in relation to the reaction rate, and high-temperature corrosion of the reaction vessel can be suppressed. It is also effective in that operations such as pressure reduction during the reaction are easy.

(9) According to the method of the present invention, the zirconium halide gas leaking from the supply device is condensed in the solid zirconium halide delivered into the reaction vessel by the supply device and is effectively captured. This has the effect that there is almost no loss of energy and there is no risk of clogging of the supply device.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of a zirconium sponge manufacturing apparatus used in carrying out the method of the present invention, Fig. 2 is an enlarged cross-sectional view of the same supply apparatus, and Fig. 3 is a manufacturing apparatus according to an embodiment of the invention. FIG. 4 is a cross-sectional view of the supply device in the apparatus, and FIG. 4 is a cross-sectional view of the manufacturing apparatus according to still another embodiment. DESCRIPTION OF SYMBOLS 1... Reaction container, 13... Supply device, 26... Operation pipe.

Claims (1)

[Claims] 1. Zirconium halide is added by a supply device into a reaction container which has previously stored an alkaline earth metal or alkali metal reducing agent inside the reaction container and has also been filled with inert gas from an internal pressure adjustment pipe for introducing and discharging inert gas. is supplied, thereby bringing the zirconium halide into contact with the alkaline earth metal or alkali metal reducing agent to perform a reduction reaction, and an operation in which a tip opening is protruded from the middle part of the reaction vessel. In the method for manufacturing zirconium sponge, the molten salt produced by the reduction reaction is extracted from the reaction vessel through a pipe, and a reducing agent is added as needed to continue the reduction reaction. At the start, a predetermined amount of zirconium halide in a solid state is directly supplied, and this solid zirconium halide is brought into contact with the above-mentioned reducing agent while in a solid state to perform an initial reduction reaction. After the completion of the reaction, the molten salt produced by this initial reduction reaction is extracted, a reducing agent is additionally charged, and a predetermined amount of zirconium halide in a solid state is directly supplied into the reaction vessel from the above-mentioned supply device, and this solid A method for producing a zirconium sponge, characterized in that the reduction reaction is continued by bringing the zirconium halide in a solid state into contact with the above-mentioned reducing agent.